Failure Analysis Of Neural Electrode And Evaluation And Optimization Of Surface Coating Properties

Implanted neural electrodes face the problem of failure in the clinical application process.In order to make a comprehensive and accurate study on the failure factors and failure mechanisms,this paper distinguishes the active failure and passive failure of the electrode,establishes the electrode failure and fault transfer model,and introduces Optimized design principles for reducing passive failure of electrodes with reducing implant damage and fretting damage,and optimized design principles for reduce active failure with optimizing electrode design and material selection,including specific optimization methods.In view of the important role of conductive polymer coatings on the surface of nerve electrodes in improving electrode performance,further research on two common coatings,polyaniline and PEDOT,is carried out,specifically:Firstly,the performances of two types of coatings prepared under different deposition methods were compared.The results show that the optimal deposition method of polyaniline conductive coating is constant current deposition under the premise of controlling the electrode charge throughput during the deposition process.The impedance is reduced by39.8%,and the CV area is increased to 6.41 times.The optimal deposition method for PEDOT coating is cyclic voltammetry deposition.Using this method,the electrode impedance is reduced by 46.3%,and the CV area is increased to 9.82 times.The two types of coatings are compared.The electrical properties of the resulting modified electrode prepared by the optimal deposition method show that the PEDOT coating has better electrical properties.Then,after simulating brain tissue wear,the electrical properties of the polyaniline coating and the PEDOT coating were compared.The results showed that the PEDOT coating still maintained relatively good electrical performance.At the same time,the tribological properties and wear mechanism of the coating were studied using a multifunctional wear tester to guide the optimization design.Finally,the PEDOT coating with better comprehensive performance is optimized.Compared with non-hydroxylated PEDOT,the electrical properties of hydroxylated PEDOT coatings prepared by polymerizing hydroxylated EDOT monomers have been improved.The results of ultrasonic cleaning tests show that hydroxylated PEDOT coatings show stronger adhesion ability to metal substrates and achieved better optimization results.